Sludge, stabilization

Organic substances present in putrefactive sludges are biologically degraded during storage, which results in hygienic defects. Therefore, they need to be stabilized. 

Sludge stabilization is a process of destruction of the microbial, easily available organic component. In practice it takes place most frequently via the sludge fermentation under aerobic or anaerobic conditions. 

---

Sludge Stabilization. Organic sludges need to be stabilized before ultimate disposal except in the case of incineration. This is usually achieved by either aerobic or anaerobic digestion. In aerobic digestion, the degradable volatile soHds are Hquefted and oxidized to CO2 and H2O. In anaerobic digestion the soHds are Hquefted and fermented to CH and CO2. 

Hassouneh O, Jamrah A, Qaisi K (1999) Sludge stabilization by composting a Jordanian case study. Bioprocess Eng 20 413 121... 

The topic of odours and odour measurement has been on the programme of the COST 68 activity since the early days. Initially, under COST 68, some studies were made of methods of assessing sludge stability 11 and these included odour assessment but little further co-ordinated work was done until the establishment in 1984 of a sub-group on odours as part of the activity of Working Party 1 of COST 681. 

Fig. 8 Bioscrubbers for the sludge stabilization of a sewage plant—central version...

Normal Operating Conditions (NOC). Under this condition the biomass remains active and the sludge stability is preserved, i.e., Ai, A2 > 0 for alH > 0. This physically means that part of the pollutant agents entering to the digester are consumed by the bacterial culture (i.e., (Ai — Si in) 0 and S2 - S2,in) 7 0). 

Jing, C Korflatis, G.P. and Meng, X. (2003) Immobilization mechanisms of arsenate in iron hydroxide sludge stabilized with cement. Environmental Science and Technology, 37(21), 5050-56. 

A related area of research would include efforts to reduce the water requirements of flue gas treatment systems. This would be especially important to the wet throwaway systems most commonly used today. Research to improve the dewatering properties of scrubber sludge could be combined with the development of techniques to separate spent and unused sorbent, thus reducing both water and sorbent consumption while also reducing the volume and mass of solid waste to be handled. The use of waste or recycled water in flue gas treatment systems would also reduce water needs. Improved sludge stabilization methods that also remove water could also lower costs associated with both waste disposal and water consumption. 

T. M. Brown, Column Leach Testing of Heavy Metal Sludges Stabilized/Solidified with Portland Cement An Investigation of Release Meehanisms, M. S. Thesis, Univ. of New Hampshire, Durham, NH (1984). 

Nako . Chaleo] Absorbent for diapers, agric. applies dehydrating agent, construction materials, fire extinguishing, waste sludge stabilization ddbamer for coatings, adhesives, food luocessing dispersant. 

A considerable proportion of the sludge dry matter is that ascribed to lipids (ether and petroleum-ether extractable substances), consisting of free fatty acids, their esters and substances incapable of undergoing saponification. The content of fatty acids in sludge is a value which is useful for characterizing the biochemical conditions in the anaerobic process of sludge stabilization. 

---